Process for the regeneration of desulfurizing catalyst



July 11, 1950 2,515,131

C. MACK PROCESS FOR THE REGENERATION OF DESULFURIZING CATALYST Filed Oct. 25, 1947 OlL m Z TREATED Ou m H1 IN 12- 1J3) ZONE.

Charles mack.- Snverzbor- {l I Qbborrzeg Patented July 11, 1950 PROCESS FOR THE REGENERATION F DESULFURIZING CATALYST Charles Mack, Sarnia; Ontario; Canada, assignor' to Standard; Oil 'Developmentfiompany, a cor poration of Delaware Application'october 25, 1947,. Se1'ial N0. 782;125'

-Claims. 1-;

The present invention'is concerned with the d'esulphurization' of oils. The invention is especially directedito the regeneration ofi catalysts such as bauxite which are utilizedzimthei de'sulphurization of petroleum oils,- particularly those boiling in the motor fuel boiling range; In accordance with the present process, spent bauxite catalyst employed in the desulphurization of oils is more fully and completely regenerated by a two stage regeneration operation whicheomprises a burning stage and an ammonia treating stage.

It is known in the art to desulphurize petro leum oils by contacting feed oilsv with" bauxite at elevated temperatures by various processes. For example, it is known to removeobjectionable' sulphur compounds from virgin feed oils'by contacting the same with bauxite at temperatures 'in' the range of from about 600 F. to 650 Ff It is also known to treat distillatesboiling in th'e- -motor fuel boilin range'secured from variouscracking operations with:bauxite at temperatures 1 in the range from about". 600 F. to 900. R, usually in the range from about 600 F. to SDO F'. The pressures employed inthe desulphurization operation may be atmospheric or as high as 300 to 400 pounds per square inch gauge. These petroleum oils boiling in the range from about 100 F. to 420 F. may be treated in the vapor orliquid phase depending upon the pressure. In general the oils are contacted with bauxite under noncracking conditions. Under these conditions substantially no-change of 'molecular weightan'dboiling range results and--Very-{little fixed gas is evolved other than hydrogen.- 'Ihe bauxiteeatalyst is thenusually regenerate'd' by burning at temperatures inthe range from'about HOW-F; to 1300 F. and higher.

In these desulphurization operations, commer-- cial bauxites are utilized which contain various concentrations of ironoxides as impurities. For example, the concentration of' iron oxide may vary from as low as 0.5% to as high as by weight based upon the alumina. One conventional procedure for the manufacture of alow iron content bauxite is to treat'a natural bauxite containing 4% to 5% iron oxide at a temperature of about 1000 F. This changes the iron to a magnetic form. The iron is then=removed by means of a magnetic separator. By-this treatment the iron oxide content of the treated bauxits is reduced to about 2 to 3%.

Also, in these desulphurization operations, the sulphur compounds which usually comprise mercaptans and organic sulphides tend to break down 5 ing one embodiment of the same.

2 to"-form hydrogen sulphide at the above-merrtioned temperature range. While the aluminum oxide in thebauxite does not react with the'hydrogen sulphide at a temperature in the range from 600 to900 R, the iron oxide present does react with thehydrogen sulphide resulting in the production of the metal sulphide. Thus, upon regeneration of the catalyst by burning-off the carbonaceous materialwith air at a temperature in the range from about 1100'F. to13'00 F.'oxidation of the iron sulphide to the corresponding sulphite and sulphate willresult. At high temperatures, as for example, 900 F. and above, the sulphite and sulphate will partlydisassociate t0 sulphur; dioxide and iron sulphide and part of these constituents Will be retained on the catalyst. Upon subsequent use of the regenerated catalyst the hydrogen sulphide form-ed fromthe break down of the sulphur compounds as de-' scribed' will rea'ct withthe sulphur dioxide generated on thecatalyst to form free sulphur which will contaminate the hydrocarbons being desulphuriz'ed'.

Ihave new discovered a process-which will sub- .stanti'allyovercome tl'ii's' diifi'culty'. My process comprises'renegerating spent bauxites utilized'in the desu'lphurizationof petroleum oils-bya two stage process; In the initial stage I burn the carbonaceous materials at elevated temperatures and in the secondary stage I treat the burnt bauxite'with ammonia, preferably at elevated temperatures.

The process of my invention maybe readily understood by. reference to the drawing illustrat- Referringspecifically to the-drawing, a petroleum oil containing undesirable sulphur compounds is introduced into treating zone I by means of feed line I0. Zone I contains a bauxite treating agent which contains as an impurity iron oxide. The treated oilsubs'tantially'free of undesirable sulphur compounds is, withdrawn from treating. zone. I' by means of line H. After the bauxite has become spent so that it will not reduce'orremove the-sulphur compounds from the oil be in treated to the desired degree, the feedoil-is then introduced into zone 2 by means of line l2. ZoneZ' isequivalentto zone i and no attempt willbe made to describe the operationofzone-Z- in detail. The treated oil is withdrawn from zone 2;by. means of linel3 and withdrawn from the system by-means 'ofline H. The spent-bauxite in zone I is treated by introducing air or other oxygen containing gas by means of line [4 in order to burn 01f the carbonaceous material.

The combustion gases are removed from zone I by means of line I5. I then purge the bauxite by means of an inert gas, which is preferably nitrogen, which is introduced into zone I by means of line 16 and withdrawn by means of line l5. Then, in accordance with my process I introduce ammonia into zone I by means of line I! and withdraw the same by means of line I 8. This stream may be handled in any manner desirable, as for example, it may be recycled or purified as desired. After the bauxite in zone I has been renegerated and the bauxite in zone 2 has become spent so that it will not satisfac- 1 torily remove sulphur compounds from the oil being treated, the feed oil stream is then reintroduced into zone I and the bauxite in zone 2 is regenerated as hereinbefore described.

My process comprises a two stage method for the regeneration of spent bauxite. In accordance with my process, I have found that the formation of free sulphur is eliminated, if after burning ofi of the carbonaceous deposits, the 1 catalyst is treated at an elevated temperature with ammonia. During this stage, the iron sulphite and sulphate are converted into the corresponding ammonium salts which are volatile lat high temperatures.

In order to further illustrate my process, the following example is given illustrating one embodiment of the same;

. Erample A plant sample of bauxite which had been repeatedly regenerated at 1200 F. in a stream of air showed the presence of iron sulphite and sulphate equivalent to 2% of S04. This bauxite was utilized in the treatment of a naphtha boiling in the range from about 100 F. to 420 F. The naphtha was also treated with fresh bauxite.

Another sample of a naphtha was treated with The results obtained are as follows:

Copper Strip M 1 ercaptans Catalyst E E E 1n Naphtha 1 Fresh Bauxite Pass.-. None.

Regenerated Bauxite Does not pass. Do. Regenerated .Bauxite treated with Pass Do.

Ammonia.

1 A. s. T. M. Designation D849-45I.

My invention specifically applies to desulphurization operations wherein petroleum oils boiling in the motor fuel boiling range are treated in the vapor phase under non-cracking conditions utilizing bauxites at temperatures in the range from about 600 F. to 900 F. It is particularly adapted to those bauxites containing from 0.5 to

F6203 as an impurity. It is especially adapted for the regeneration of bauxites containing in excess of 3% Fezos as an impurity. The temperature used in the burnin o initial stage may be any satisfactor temperature, but generally is in the range from about 1000 F. to 1300 F.

The temperature employed in the secondary stage, or ammonia treating stage, is preferably in the range from 600 F. to 900 F. It is very desirable that this ammonia treating operation be conducted in an inert atmosphere, preferably in an atmosphere of nitrogen or flue gas.

I claim: 1

ljlmproved process for the removal of mercaptans and organic sulphides from petroleum oils boiling in the gasoline boiling range which comprises contacting said oils with bauxite containing iron oxide as an impurity at a temperature in the range from about 600 F. to 900 removing said bauxite from the feed oil after the same has become spent to the extent th-at'the bauxite will not satisfactorily remove said mer- 'captans from the oil to the desired extent, burning said bauxite with an oxygen containing gas at a temperature in the range from about 1000 to 1400 F., placing said burned bauxite in an inert atmosphere and treating the same with ammonia in a secondary stage, removing said ammonia and again contacting the bauxite with feedbil containing mercaptans. H J

2. Process as defined by claim 1 Wher'ein'the temperature employed when treating said bauxite with ammonia is in the range from about 600 F. to 900 F. i

3. Process as defined by claim 2 wherein the concentration of the iron oxide (FezOs) in said bauxite is in the range from about 3% to 10%.

4. Improved process for the regeneration of bauxite containing more'than about 3% of iron oxide as an impurity, said bauxite having been employed in the desulfurization of oils which- 5. The process defined by claim 4-wherein the bauxite is treated with ammonia in'a secondary stage in an inert atmosphere at a temperature of I about 800 F. I I

CHARLES MACK. 1

REFERENCES CITED,

The following references are of record in th file of this patent:

UNITED STATES PATENTS Number Name Date 2,016,271 Buell et a1. Oct. 8, 1935 2,160,874 Kinsel June 6, 1939 2,162,319 'Schulze June 13, 1939 2,225,782 Ipatieff et al Dec. 24,1940 2,225,811 Wells Dec. 24, 1940 2,242,387 Boyd May 20, 1941 2,267,735 Ipatiefi et a1. Dec. 30, 1941 2,326,369 La Lande Aug-1 0, 1943 2,331,343 Phillips Oct. 12, 1943 2,412,868 Brown Dec. 17, 1946 FOREIGN PATENTS Number Country Date 337,348. Great Britain Oct. 23, 1930 OTHER. REFERENCES Helmers et 'al., Catalytic Desulfurization Over Bauxite, Petroleum Processing, Feb, 1948, pages 133 to 138. 

1. IMPROVED PROCESS FOR THE REMOVAL OF MERCAPTANS AND ORGANIC SULPHIDES FROM PETROLEUM OILS BOILING IN THE GASOLINE BOILING RANGE WHICH COMPRISES CONTACTING SAID OILS WITH BAUXITE CONTAINING IRON OXIDE AS AN IMPURITY AT A TEMPERATURE IN THE RANGE FROM ABOUT 600*F. TO 900*F., REMOVING SAID BAUXITE FROM THE FEED OIL AFTER THE SAME HAS BECOME SPENT TO THE EXTENT THAT THE BAUXITE WILL NOT SATISFACTORILY REMOVE SAID MERCAPTANS FROM THE OIL TO THE DESIRED EXTENT, BURNING SAID BAUXITE WITH AN OXYGEN CONTAINING GAS AT A TEMPERATURE IN THE RANGE FROM ABOUT 1000*F. TO 1400*F., PLACING SAID BURNED BAUXITE IN AN INERT ATMOSPHERE AND TREATING THE SAME WITH AMMONIA 